<?php
http_response_code(404);
    header("Access-Control-Allow-Origin:*");
    header('Access-Control-Allow-Methods:POST');   
    header('Access-Control-Allow-Headers:x-requested-with, content-type');
    $mysqli = new Mysqli("localhost","root","root","db_yidianzu");
    if($mysqli->connect_errno){
        die();
    }